Bryant Heat Exchange Failures - http://www.hvacmechanic.com/ Forums


Original message

momof3kids

71.173.186.199

"Bryant Heat Exchange Failures" , posted Tue 4 Mar 12:56user profileedit/delete messagepost reply

I am hoping that someone with some HVAC knowledge can help me. Basically, I have a home with split furnaces & I have had the bad luck of having 2 heat exchange failures with my furnaces. My unit in the lower level was included in the class action lawsuit against Carrier/Bryant. (The unit that I replaced it with is also involved in the lawsuit! More of my bad luck...) My unit that was in my upstairs was a Bryant 349MAV. It was not included in the lawsuit & I can not find an answer as to WHY? My house is 14 years old & I have had to replace BOTH of my furnaces. I have talked to the Bryant help line to no avail. They kept on referring me to my local distributor. He told me that the furnace I had (the 349 MAV) was a 80% efficiency unit & did not have 'polypropane' in the heat exchanger that has failed. I countered with the fact that it IS a 90% efficient unit, but I do not know what type of material the heat exchanger was constucted with. The manual says 'constructed with corrosion-resistant steel' which may (or may not be) the polypropane. Does anyone have any knowledge on this that may help me recoup the over 5000.00 I have had to spend on new furnaces these past 5 years? Thanks

Momof3kids

 


Replies:

Freon

70.157.177.45

"Re(1):Bryant Heat Exchange Failures" , posted Tue 4 Mar 15:06:user profileedit/delete messagepost reply

I would first do one simple test. Measure the heat rise across the heat exchanger and compare it to the listed (on the furnace data tag) allowable range. A furnace may be designed to run the heat exchanger up to 140 degrees but the high limit may be 180. Therefore it's possible to run the furnace too hot for the heat exchanger's health yet not so hot as to trip the high limit safety.

Many heat exchanger failures are due to too great a temperature rise and that's usually the result of poor duct design. If you find your temperature rise is on the high side, fixing that problem will hopefully prevent future failures.

Also you should determine the exact mode of failure. Was it separation at a seam, rust-through or something else? Knowing how your furnace heat exchanger failed will help determine what remedies you may have. Then review the class action filings (they should be very technically detailed) and see if there are similarities to your failure.

[this message was edited by Freon on Tue 4 Mar 19:46]